Electrochemically modulated SERS detection of procaine using FTO electrodes modified with silver-decorated carbon nanosphere

Procaine belongs to a class of drugs whose excessive dosage results in cardiac arrest and several allergenic reactions. Therefore, its continuous monitoring is crucial for sustainable health management during treatments. In this study, a reliable electrochemically modulated sensing approach for the quantitative detection of procaine using in-situ surface-enhanced Raman scattering (SERS) was developed. A fluorine-doped tin oxide electrode modified using silver carbon nanosphere (AgCNS-FTO) was designed, electrochemically evaluated, and used as an efficient substrate. The investigation of the electrochemical interaction of procaine molecules towards the modified electrode revealed that upon the optimum electrochemical pre-concentration potential (-0.1 V) and time (400 s), significant enhancements in the intensity of key Raman peaks corresponding to the NH₂ bending, C=C stretching, CH₂ twisting and C-N stretching modes could be observed. The reported approach enabled a remarkable sensitivity and selectivity towards procaine, resulting in an unprecedented detection limit down to the level of 10^-13 M. The reproducibility and stability of the modified FTO electrode were ensured over a duration of one month, and a low RSD of 2.4% was achieved. First-principles calculations proposed the interactive nature between the AgCNS surface and procaine molecules, while the possible protein-ligand binding with the chemokine receptor CXCR4 predicted an anti-inflammatory tendency of procaine with a binding energy of – 5.7 kcal/mol for the pose with the highest affinity. The electrochemically modulated SERS approach developed in the present study shall facilitate the efforts towards the practical quantification of procaine in clinical samples and could be extended to other structural analogues.